Device for cutting sponge rubber or the like



-2 SheetS-Sheet l July 31,l '1945,*1 V F. G.-PlERcE ErAL v DEVICE vFOR lCUTTING sPoNGE RUBBER 0R THE LIKE v f .1 Fil'edApril 9, 1943 July 31, 1945. F. G. Pin-Resum 2,38Q,7 87

DEVICE FOR CUTTING SPONGE RUBBER 0R THE LIKE.`

Filed April' 9,v 194s 2 sheets-sheet 2 a er .em

GH... fr. 4MM

,UNITED STATES PATENTV .orifice nevica non cU'rriNG sroncn nonnen y -on zum Lum Frank GPierce, Des Moines, Iowa, and August H.

De Groote, Rolling Prairieflnihnlignorsto Mishawaka Rubber '& Woolen Manufacturing 4 Commpany, Mishawaka, Ind., a corporation 'of In Application April 9, 1943, Serial No.l 482.4965;

The present .invention relates to a' means for Y severing or trimminga mass oi cellular elastithat -accompanies the 'cutting results in" such and unevenness that the cutting is rough and unsatisfactory.

By the device of the present invention, these n .s claims. (ciao-22o) a cutting teeth, the guard being in position and covering the cutter teeth; Fig. 2 is a similar view showing the guard retracted to expose the cutter teeth for the operation of the device; v

Fig. 3 is an enlarged diagrammatic view illus- I trating the manner in which the cutting teeth with the bottom plate thereof removed to disf sever the cell walls oi a piece of sponge rubber;

Fig. 4 is an enlarged detail rsectional view on theline I-I oi Fig.3:- 1 n Fig. 5 is a bottom view of the cutting device close details of the internal construction;

Fig. 6 is a transverse sectional view of the cutting device taken on the line 6--8 of Fig. 5;.

Fig. 7 is a lateral edge view of one of the cutters;

diillculties heretofore experienced are eliminated I as the present cutter engages and cuts the material without appreciable compressionror distortion thereof and result.

A pair of .reciprocating cutter members are employed, one'overlyin'g the other and each with a vseries of forwardly extending'pointedteethv operating oppositely to themovements ofthe other series of teeth so that there are, in effect, two saws the reciprocating movements of each of which are opposite or counterwise to the reciprocating movements ofthe other saw.

Thus small portions of the soit material are engaged between the oppositely moving teeth and severed, and,` withthe cellular material, the

points of the teeth 'enter the cells and sever the neat and smooth cut surfaces intervening walls without anyv appreciable com-l pression or distortion of. the material and thereby insure a neat "clean cut without the roughness.

irregularity and unevenness that has been experienced with previous methods of cutting such The principal objects of our invention are to Aprovide an improved means for satisfactorily cutting or severing soft compressible materials suchl as latex foam sponge; vto avoid any appreciable compression or displacement of the material in the cutting operation which might contribute yto unevenness or inaccuracy of cutting and to insure a neat clean and accurate cutting oi the material; these and other objects being accomplished as pointed out hereinafter and as shown in the accompanying drawings in which: j

Fig. 1 is a perspective view of a sponge rubber cutting means embodirinsthe`V features oi' the Fig. 8 is a rear viewl of one of the cutters;

Fig. 9 is a top edge ew of -one ofthe eccentric blocks through which eciprocating movement is imparted to a. cutter;"and

Fig. 10 is a fragmentary view of a cuttershowing a modied form of cutter teeth. y

Thek cutting device of the present. invention includes a ilat nozzle shaped casing or housing i having a straight front edge 2 from which the teeth 3 oi? a pair o f oppositely reciprocating cutter members i1 and i8' project. At the rear end of the casing i is a hollow cylindrical shank member I which serves as a handle and through which a flexible shaft 8 is connected to the l operating'mechanism of the cutter, said exible shaft 6 being secured to the rear end of the Ylfiandiel by a suitable coupling 5.

.A safety device is provided to cover the cutter teeth when the'device is not in actual use and while the cutter members are, inoperative or in active, and for this purpose there is provided a' guard 'I in the form of a substantially'straight iiat bar overlying andrcovering the 'cutter teeth 3, as indicated in Fig. 1,'and capable of being drawn rearwardly toa position as shown in Fig. 2 so 4as to expose the cutter teeth I for use. A pair of arms 8 extend rearwardly from the guard 1 and through guides 8' to a position at or in rear of the rear end of the easing I, where they are connected by a cross bar 9, the arms 8 and the cross bar 9 constituting a substantially U- shaped yoke. Pivotally connected as at it to the cross bar portion 9 is an upstandingarm l! oi a bell crank lever which is pivoted at i@ to the casing l, said arm il 'being apertured or ring shaped as shownv so that the hane li es tenda` `loosely therethrough. rihe other arm i2 present invention. and showing a guard' forthe 65 .of the bell crank extends forwardly from the tcp its operative of the arm-II and overhangs the casing I. Beneath the front free end of the arm I2 is a suitable spring I3 bearing in opposite directions against the top of the casing I and the underside of the arm I2, s'o as to maintain the latter inl an elevated position with the guard 1 at its `front limit and covering the cutter teeth 3. For

moving the guard 1 rearwardly, to uncover the cutter teeth, there is provided a hand lever I4, fulcrumed at its front end as at I5 on the top of the casing I, the underside of the forward. portion of the lever I4 being provided with a cam member I6 in cooperative relation with the top of the arm I2 towards the front free end thereof. The lever I4 extendsrearwardly across the top of the shank or handle 4, whereby the shank 4 and the lever I4 may be grasped in the pahn of the hand so as to swing the lever I4 downwardly on. its fulcrum I5 to press the cam I6 against the forward end of the arm I2 to .depress same and move the bottom portion of the Aarm II rearwardly, thereby to move the yokearms 8 rearwardly and withdraw the guard 1 from its normal operative position as shown in Fig. 1, to its inoperative position vas shown in Fig. 2, thus exposing the cutter teeth 3 for operation. Upon releasing the grip'of the hand, the spring I3 will act tovreturn the lever I4 to its normal position and to move the guard 'I forwardly into v a position overlying and covering the cutter teeth 3. K

The cutter members I1 and I8 are alike, except that the member lI1 is slightly shorter than the member I8, and they are mounted for lateral reciprocation in a slideway in the bottom of the casing I. The cutter I1 is directly above the cutter I8, and both have a pair of transverse slots 2l vtherein which engage guide lugs 22 which extend downwardly from the casing I into the slideway 20 and confine the operation of the cutters. I1 and I8 to a straight line movement parallel to the forward edge 2 of the casing throughwhich the teeth 3 project.

A bottom plate 23 closes the slideway- 20 at the bottom and slidably confines the cutters I1 and `I8 therein, this plate being secured to the cas- .ing by screws (not shown) which engage screw holes 24 in the bottom of the casing I and the guide lugs 22. A l

Each cutter member I-1 and I8 has its rear end upturned and notched to provide laterally spaced upwardly extending arms lying in planes at right anglesto the axis of the shank-or handle 4, those of the cutter member I1 being in-v dicated at I1* and of the cutter member I8 at I8*,

and it will be observed that the arms I1* of the' cutter member I1 are directly in front of the arms Il* of the cutter member'l8 and to this extent the cutter-member I1 is shorter than the cutter member I8 as previously mentioned.

A shaft, which is connected with and operated bythe flexible shaft 6, extends lengthwise through the shank or handle 4 and has the inner end 24 thereofprojecting. into the notches between the upturned arms I1L and I8* of the cutter members I1 and I8. Said inner end 24 of said shaft has a pair of eccentrics I1b and I8b secured thereon by the nutl.28, the eccentric I1 lyingin the plane of the upturned arms I1* of the cutter member I1 and the eccentric I8b lying inthe planeof the upturned arms I8* of the cutter member I8, and these eccentrics are fixed on the shaft 24 each at a half turn around the axis of the shaft 24 from the other so that they act oppositely. f' r f Each pair of arms I1* and I8* constitutes a slideway for a block in which the respective eccentric I1b or |81 operates, the block which is slidably mounted between the arms I1* being indicated at I1c and the sliding block between the arms I8Il being indicated at I8, and each block I1c and IIIc has a circular opening 28 (see Fig. 9) in which its respective eccentric I1b or IBb is engaged.

These blocks I1 and I8 have V-shaped notches 21 (see Fig. 9) in their lateral edges and the inner edges of the. arms I1* and I8* are V- shaped as indicated at 28 to fit in the V-notches 21 of the respective. block I1 or I8c to hold each block in place between its respective arms I1* or I8.

With this construction, as the shaft 24 is rov tated the eccentrics I1b and I8b rotate therewith while movement is imparted to the cutter memthereof. v

`by'the hand of theV user in the manner shown ber I8 to the left and vice versa.

The manner in which the cutting implement operates to sever a piece of sponge rubber is i1- lustrated diagrammatically in Figs. 3 and 4'of the drawings wherein 29 designates a piece of sponge rubber, a portion of which has been broken away to expose `the cellular structure In using the implement, it is grasped in Fig. 2 so as to retract the guard 1 and expose the cutter teeth 3, whereupon the cutter teeth are brought up against the piece or mass of sponge rubber 29 and the pointed ends of the cutter teeth are thrust into the rubber material so that when the cutter blades are reciprocated they will simultaneously sever the thin walls between successive cells without compacting or distorting the sponge rubber mass. Of course, the cutting device is moved forwardly so as to thrust the points of the cutter blades into the rubber material and the continued reciprocating movement of the blades will continue the operation 'of severing the relatively thin walls between cells, whereby a clean and relatively smooth cutting or severing of the cellular material is accomplished in a very simple and effective manner. Itvwill here be noted that each pair Aof cooperating cutter teeth 3 on opposite blades produce a shearing action,but this shearing action is on a verythin portion of the rub- The teeth 3 oi' the cutters may be ordinary pointed cutter teeth such as shown in Figs. 3, 4 and 5, but we have found itadvantageous to employ more sharply pointed or more acutely vangled teeth such as shown in Fig. 1 0, and we have further found it advantageous and to facilitate cutting to notch the lateral edges of the teeth as indicated at 8l in Fig. 10.

While we have shown and described our invention in a preferred form, we are aware that various changes and modifications may be made without departing from the principles of our invention, the scope of which is to be determined by the appended claims.

What is claimed is:

l. A device for cutting cellular elasticay yieldable material comprising a pair of parallel oppositely reciprocatory blades having cutter teeth in cooperative relation, a housing for the l blades, the cutter teeth projecting at the front of the housing, ya hollow shank extending from the rear of the housing and constituting a handle for'the device, a coupling carried by the rear end of the combined shank and handle for connection with flexible shafting, a guard member for covering the cutter teeth and comprising a bar normally overlying and extending outwardly beyond said teeth, means for maintaining said guard member in said normal position, and means for withdrawing the guard member to expose the teeth for use in the operation of the device,

2. A device for cutting cellular elastically yieldable material comprising a pair of parallel oppositely reciprocatory blades having cutter teeth in cooperative relation, a housing for the blades, the cutter teeth Vprojecting at the front of the housing, a hollow shank extending from the rear of the housing and constituting a hanin cooperative relation with the arm to move the arm against the action of the spring.

3. A cutting device of the class described comprises a casing having a slotted edge, a pair of oppositely reciprocable plates in the casing, each plate having a series of cutter teeth projecting through said slotted edge of the casing, a han dle projecting rearwardly from the casing and having a rotatable shaft therein with a pair of eccentrics at the forward end thereof in the casing, and each of the aforesaid plates having spaced upturned portions between which a respective one of the eccentrics operates to impart opposite reciprocation to the plates.

4. A shearing device of the type described comprising, a housing having a slotted front, a. pair of cutting blades positioned in said housing in face to face relationship and having teeth projecting outwardly through said slot, means Within said housing for simultaneously reciprocating said blades in opposite directions, said blades having registering guideways, and a guide element projecting into said guideways to conne the movement of said blades to straight line movement parallel to the housing slot.

5. A shearing device of the typedescribed comprising, a housing having a slotted front, a pair of cutting blades positioned in said housing in face to face relationship and having teeth.

projecting outwardly through said slot, each blade having a pair of laterally spaced upstanding arms within said housing, an apertured block held between each of said pairs of arms in vertically slidable manner, and an eccentric engaged within the aperture of each of said blocks for simultaneously reciprocating said blades in opposite directions.

FRANK G. PIERCE. AUGUST H. DE GROOTE? 

